1. Technical Field
The present invention generally relates to a developer conveyance device to transport developer and further to an image forming apparatus, such as a copier, a printer, a facsimile machine, a plotter, or a multifunction peripheral (MFP) including at least two of coping, printing, facsimile transmission, plotting, and scanning capabilities, that includes a developer conveyance device.
2. Description of the Background Art
In image forming apparatuses, copiers, printers, facsimile machines, plotters, and MFPs, positive-displacement pumps are often used to transport developer consisting essentially of toner (toner particles) and carrier (carrier particles).
Positive-displacement pumps generate pressure by repeatedly varying the volume of space thereinside and use the pressure to draw in air or powder externally and then discharge the air or powder.
Examples of positive-displacement pumps include diaphragm pumps, piston pumps, and bellows pumps.
For example, JP-2005-062648-A proposes a configuration that employs a diaphragm pump to transport toner from a toner reservoir to a toner hopper disposed in an upper portion of a developing device.
Additionally, JP-2002-284345-A proposes a configuration that employs a uniaxial eccentric screw pump to suck in toner from a toner cartridge and transport toner to a developing device.